[xadhominemx]

Yes of course the equipment breaks down but older equipment is easy to repair. It is very rare for a fab to be decommissioned and the equipment scrapped - in fact I have never heard of this happening to any production facility with 6” or larger wafers. That equipment will go to de-bottlenecking at some other fab and net production capacity for the node will increase.

Obviously many very old chips are out of production but not because the equipment broke down and was never repaired.

[ajross]

The corrollary to your point then is that all these fabs have immense idle capacity of exiting installed tools which they aren't using but retain simply because nothing ever "broke down"? Obviously that's ridiculous.

You're interpreting me pedantically while actually agreeing with my point, I think. Old processes don't have the capacity they used to[1]. If you don't like "stuff breaks" then how about "eventually the ROI on the equipment goes negative relative to the business so the line is idled and the fab real estate repurposed to make more profitable modern stuff." OK?

[1] Which, again, is just a "duh" kind of point and I can't believe we're arguing about it.

[xadhominemx]

No, old processes have very nearly the same capacity the used to, some even more. Several foundries are adding 8” capacity right now.